package com.ejyi.demo.design.model.aabstract.factory;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import java.io.File;

public class XMLUtil {
    // 该方法用于从 XML 配置文件中提取具体类类名，并返回一个实例对象
    public static Object getBean() {
        try {
            // 创建文档对象
            DocumentBuilderFactory dFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = dFactory.newDocumentBuilder();
            Document doc = builder.parse(new File("config.xml"));

            // 获取包含类名的文本节点
            NodeList nl = doc.getElementsByTagName("className");
            Node classNode=nl.item(0).getFirstChild();
            String cName=classNode.getNodeValue();

            // 通过类名生成实例对象并将其返回
            Class c=Class.forName(cName);
            Object obj=c.newInstance();
            return obj;
        }
        catch(Exception e) {
            e.printStackTrace();
            return null;
        }
    }
}
